PROJECT SUMMARY/ABSTRACT Methamphetamine (MA) dependence and HIV infection are highly comorbid conditions, the combination of which greatly increases the likelihood of poor disease outcomes, in part due to elevated rates of antiretroviral (ARV) nonadherence. Both HIV and MA are associated with poor medication management, a multifactorial health behavior that underlies successful adherence to ARV therapy. Adding to the risk of poor medication adherence in this group, the neurotoxic effects of comorbid HIV and MA preferentially impact frontostriatal brain regions, resulting in an increased prevalence of neurocognitive disorders that affects up to 60% of the HIV/MA population. The profile of neurocognitive impairment in HIV/MA includes prominent deficits in learning, which is a cognitive ability that is critical for optimal medication management. Despite the prevalence and ecological relevance of poor medication management in HIV/MA, to date there are no empirically validated neurocognitive techniques aimed at improving medication management in this high-risk population. One neurocognitive technique that has been effective for improving learning as well as long-term retention within cognitive psychology and applied educational psychology studies is interleaved practice, in which different types of material to be learned are practiced in a mixed, or interleaved, fashion, instead of being blocked by type (e.g., abcbcacab vs. aaabbbccc). Within healthy populations, the beneficial effects of interleaved practice have been documented across a wide range of skills and knowledge bases, many of which are relevant to medication management behaviors (e.g., numeracy). Accordingly, the proposed F31 dissertation project seeks to: 1) evaluate the efficacy of interleaved practice (versus standard blocked practice and no practice) on numerical medication management performance in MA/HIV; 2) determine whether interleaved practice (versus standard blocked practice and no practice) is associated with greater transfer of learned skills to different medication management problems; and 3) explore potential demographic, psychiatric, HIV disease, health literacy, and addiction effects on the interleaved practice effect on medication management in MA/HIV. Given the current absence of such techniques in this population, results from this project may inform future projects that aim to develop novel cognitive techniques for enhancing adherence and other health-related behaviors in HIV/MA. Through the implementation of this dissertation research project and the comprehensive training plan entailed in this F31 proposal, the applicant will enhance her scientific knowledge, research methodology, and ability to further contribute to the fields of neurocogniton, everyday functioning, and health behavior functioning in neuroAIDS and addictions. Moreover, the opportunities afforded by this F31 training and research plan will be extremely valuable in consideration of the applicant's short- and long-term goals toward becoming an independent academic neuropsychologist dedicated to improving the lives of persons living with HIV infection and addictions.